Automobile congestion is too often portrayed as mere nuisance or inconvenience. A new study from Germany, which we heard about via Streetsblog Network member blog The Hard Drive, reminds us that it is much more than that. The study, presented at the American Heart Association’s 49th Annual Conference on Cardiovascular Disease Epidemiology and Prevention last week, shows that being in a traffic jam — whether in a car, on a bike, or on a bus — can triple a person’s chance of having a heart attack:

“Overall, time spent in any mode of transportation in traffic was associated with a 3.2 times higher risk than time spent away from this trigger,” the study says.The researchers didn’t try to pinpoint the reasons for the increased risks, but stress is a suspect. Another one: the exhaust and air pollution coming from other cars, the authors said.

Past studies have discovered that pollution from car exhausts causes arteries to stiffen, resulting in higher blood pressure and reduced blood flow to the heart.

Being stuck in traffic can dramatically increase your chances of having a heart attack, scientists warned today.

German researchers analysed 1,500 heart attack patients, and found they were three times more likely to suffer a heart attack for an hour after being in traffic — and an increased risk was present for six hours.

They say stress combined with pollution could be to blame. “Driving or riding in heavy traffic poses an additional risk of eliciting a heart attack in persons already at elevated risk,” said Professor Annette Peters of the research centre, the Helmholtz Zentrum München.

“One potential factor could be the exhaust and air pollution coming from other cars,” said Professor Peters.

“But we can’t exclude the synergy between stress and air pollution that could tip the balance.”

A new study from researchers in Germany shows traffic jams — long considered sources of stress, frustration and road rage — can also be linked to heart attack.

The study of more than 1,400 heart attack patients found they were more than three times more likely to have been in traffic within an hour of experiencing a heart attack, than not.

The research was presented at the American Heart Association’s 49th Annual Conference on Cardiovascular Disease

In total, 1,454 heart attack patients were interviewed by the researchers, who used a standardized set of questions to gauge patients’ exposure to traffic in the preceding hours.

They found that most of those who were in traffic prior to having a heart attack were driving a car. But others were riding public transit or a bicycle, before the onset of the attack.

Overall, those who spent time in traffic, regardless of the mode of transportation, faced a 3.2 times higher risk of heart attack than those who did not.

Exposure to traffic had the greatest effect on women, elderly males, the unemployed and patients with a history of angina, the study found.

“Driving or riding in heavy traffic poses an additional risk of eliciting a heart attack in persons already at elevated risk,” Annette Peters, the lead author of the study, said in a release.

“In this study, underlying vulnerable coronary artery disease increased the risk of having a heart attack after driving in traffic.”

The study wasn’t intended to find clear reasons why traffic may increase heart attack risk, but Peters said the exhaust and air pollution from other cars could be a contributing factor.

“But we can’t exclude the synergy between stress and air pollution that could tip the balance,” she said.

The new research corroborates earlier work by the same team, published in 2004, that looked at 691 patients, with similar results.

“It is reassuring that we were able to reconfirm this association in an extended case series. Now it’s important to find out what is behind this, whether it is air pollution or stress or both,” Peters said.

One of the more surprising results of the recent study is that women face a five times higher risk than men of having a heart attack after being in traffic.

The same research team’s previous work showed that strenuous activities, such as playing sports or shovelling snow, resulted in a five to six times higher risk of heart attack following the activity.